1. Field of the Invention
The present invention relates to an image forming technology applicable to both biological and industrial fields, and more particularly, among such image forming technology, to a laser scanning microscope.
2. Related Background Art
The conventional ordinary laser scanning microscope is generally designed to detect the total amount of light transmitted or reflected by a specimen.
There is also known a configuration having a one-dimensional image sensor on a position conjugate with the plane of the specimen, but such configuration is equivalent to the detection of total amount of light as the light spot moves on the sensor in the scanning operation.
As a development from such ordinary laser scanning microscope, there is known a laser scanning microscope as disclosed in U.S. Pat. Nos. 4,800,269 and 4,734,578, in which the photosensor device is divided into two or more segments and such divided photosensor device is placed at the exit pupil of an optical system with positive refractive power, and the electrical signals respectively obtained from the divided portions of the photosensor device are suitably processed. Such configuration combined with signal processing allows to obtain both a differential image of the specimen and an ordinary bright-field image, and a dark-field image can also be obtained by the use of a light-shielding mask.
Also S. Kawata et al. reported, in Laser computed-tomography microscope, Applied Optics, 29 (1990) 3805, the technology for obtaining a tomographic image utilizing computation (hereinafter called CT image) of the optical characteristics of the specimen.
Also Japanese Patent Application Laid-Open No. 3-21913 discloses the use of a two-dimensional image sensor as the photosensor device for the laser scanning microscope.
U.S. Pat. Nos. 4,800,269 and 4,734,578 explain that the laser scanning microscope disclosed therein can provide both the differential image of the specimen and the ordinary bright-field image, and also the dark-field image in combination with the use of the light-shielding mask, but do not suggest any other image information.
Also according to the technology reported by S. Kawata et al., Laser computed-tomography microscope, Applied Optics, 29 (1990) 3805, in order to obtain the CT image of the optical characteristics of the specimen, there are required images formed by illuminating the specimen from various observing angles, and it is totally impossible to realize such function with the detecting method in the conventional laser scanning system.
Also in the technology disclosed in Japanese Patent Application Laid-Open No. 3-21913, the image sensor is provided on the conjugate plane of the light spot and can therefore only provide the ordinary bright-field image, from the standpoint of collection of image information.